Modified glycidyl carbamate resins

ABSTRACT

The invention relates to alcohol-modified glycidyl carbamate resins wherein at least some of the glycidol groups in the resin have been replaced with an alcohol. The invention also relates to coating compositions containing the resins.

GOVERNMENT SUPPORT

This invention was supported by the Department of the Navy under Grantnumber 861-NVY-2S/NDSU Prime:N00024-05-C-4139. The government hascertain rights in this invention.

FIELD OF THE INVENTION

The invention relates to glycidyl carbamate (GC) resins that have beenmodified to substitute at least some of the glycidyl groups withalcohol-derived groups. The modified GC resins may be crosslinked andused in coatings.

BACKGROUND

The synthesis of the glycidyl carbamate functional group by the reactionof an isocyanate functional compound and glycidol is known to thoseskilled in the art.

Farissey and Nashu (Journal of Heterocyclic Chemistry, 1970, 7, 331-333)disclose the synthesis of a glycidyl carbamate model compound and theintramolecular rearrangement reaction at elevated temperatures to ahydroxyoxazoline.

U.S. Pat. No. 4,397,993 discloses oxirane-containing polyurethanepolymers where the oxirane is part of a glycidyl carbamate group.Crosslinking of the polymer is effected by reaction of the polymer withan epoxy crosslinking agent which can be a polyol or polyamine. Thispatent also discloses a “self-crosslinkable” polymer, however theself-crosslinkable polymer incorporates unreacted isocyanate groups.

U.S. Pat. No. 4,950,722 discloses the synthesis of an unsaturated epoxythat contains carbamate functionality. Mixtures of this compound withconventional epoxy resins as well as the vinyl copolymerization withother unsaturated monomers was described.

Chen et al. (J. Applied Polymer Science, 51, 1199 (1994); J. AppliedPolymer Science, 52, 1137 (1994)) discloses the preparation ofglycidyl-terminated polyurethane resins. Polyamines were used tocrosslink the polymers. Blends of the glycidyl-terminated polyurethaneresins with conventional epoxy resins were also prepared and crosslinkedwith polyamines.

Edwards, et al. (Polymer Preprints, 44(1), 144 (2003); PolymerPreprints, 44(1), 54 (2003); Polymeric Materials: Science andEngineering, 90, 455 (2004); Prog. Org. Coat., 57, 128-139 (2006))discloses the synthesis of multifunctional glycidyl carbamate functionaloligomers from polyfunctional isocyanates and glycidol. Theself-crosslinking reaction to form coatings with good performance wasalso described.

Edwards, et al. (Polymer Preprints, 45(1), 935 (2004); JCT Research2(7), 517-528 (2005)) described the crosslinking of the multifunctionalglycidyl carbamate functional oligomers with polyfunctional amines toform hard and flexible coatings having good solvent resistance.

The glycidyl carbamate resins described by Edwards, et al. are thereaction products of multifunctional isocyanates with glycidol. Two suchresins are illustrated below and are based on the hexamethylenediisocyanate triisocyanurate trimer (IGC) and biuret trimer (BGC),respectively.

These resins can be self-crosslinked or crosslinked with amines toproduce coatings. However, the resins have very high viscosity and alarge amount of solvent is needed to make coatings, especially coatingsthat can be applied using spray, brush, or roller application methods.

Thus, what is needed in the art is a way of reducing the viscosity whilemaintaining the reactivity and good properties of these glycidylcarbamate functional resins. This invention answers that need.

SUMMARY OF THE INVENTION

The invention relates to alcohol-modified carbamate functional (GC)compounds of formula (I), (II), (III), or (IV). Coating compositions maycontain one or more of these GC-functional resins, other GC-functionalcompounds, a curing agent, and an organic solvent. The alcohol-modifiedGC compounds of formulas (I)-(IV) where the variable n is 0 arethemselves a separate embodiment of the invention. The inventionprovides methods for making a solvent-based coating composition andmethods of coating substrates with a solvent-based coating compositionof the invention.

The invention also relates to a method of making an alcohol-modifiedglycidyl carbamate resin containing glycidyl carbamate functionalcompounds, comprising the step of substituting about 5% to about 45% ofthe glycidyl groups in the glycidyl carbamate functional compounds withan alcohol. In a separate embodiment, the GC-functional resin is areaction product of an isocyanate having at least three isocyanategroups, glycidol, and an alcohol, where the equivalent ratio of glycidolto alcohol ranges from 1:2 to 49:1.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a chart depicting the viscosity of various glycidyl carbamateresins.

FIG. 2 is a chart depicting the crosslink density of various glycidylcarbamate resins.

FIG. 3 is a chart depicting the TGA curves of various glycidyl carbamateresins crosslinked with PACM.

FIG. 4 is a chart depicting the TGA curves of various glycidyl carbamateresins crosslinked with Ancamide 2353.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to coating compositions which contain analcohol-modified GC compound of any of formulas (I)-(IV), optionallyother GC-functional compounds, optionally a curing agent, and optionallyan organic solvent. The alcohol-modified GC compounds of each offormulas (I)-(IV) are themselves separate embodiments of the invention.

The alcohol-modified GC compounds useful in the invention can bedescribed by the following general formulas (I), (II), (III), and (IV):

Formula (I) is representative of a triisocyanate glycidyl carbamatefunctional compound; formula (II) is representative of a biuret glycidylcarbamate functional compound; formula (III) is representative of animinooxadiazine dione compound; and formula (IV) is representative of amulti-functional allophanate compound.

X represents either the glycidyl group:

or an alkyl group derived from an alcohol, represented by:

wherein at least two of the X moieties in each compound are representedby the glycidyl group.

For the alcohol-modified GC compounds of formulas (I)-(IV), n may rangefrom 0 to 50 and preferably ranges from 0 to 10, and more preferablyfrom 0 to 5. In certain embodiments, n ranges from 1-5, and in otherembodiments, n is 0. When n is other than 0, the modifying alcohol groupis an ether alcohol group containing one or more ethyleneoxy groups.GC-functional compounds of formulas (I)-(IV) where n is 0 represent aseparate embodiment of the invention.

R₂ is independently an optionally substituted, divalent C₁-C₁₅ alkyl,optionally substituted divalent C₃-C₁₅ cycloalkyl, or a group selectedfrom

Preferably, R₂ is a divalent C₁-C₁₅ alkyl, more preferably a C₃-C₁₀alkyl, even more preferably a C₃-C₈ alkyl, and most preferably —(CH₂)₆—.R₃ is independently an optionally substituted C₁-C₂₂ alkyl, preferably aC₁-C₁₅ alkyl. For embodiments of the invention where n is 1 or more, R₃is preferably C₁-C₆, and more preferably C₁-C₃. For embodiments of theinvention where n is 0, R₃ is preferably C₃-C₁₀, more preferably a C₄-C₈alkyl, and most preferably a n-butyl, iso-butyl, or a 2-ethylhexylgroup.

In formula (IV), the variable m ranges from 1-15, preferably 1-7, andmost preferably 1-4. This includes trifunctional allophanate resins(where m=1) and tetrafunctional allophanate resins (where m=2).

Preferred compounds include those represented by formulas (Ia) and(IIa):

The term “alkyl” includes straight and branched alkyl groups. Asindicated above, R₂ and R₃ may be substituted with any number ofsubstituents or functional moieties. Examples of substituents include,but are not limited to, halo substituents, e.g. F; Cl; Br; or I; ahydroxyl group; a C₁-C₆ alkoxy group, e.g., —OCH₃, —OCH₂CH₃, or—OCH(CH₃)₂; a C₁-C₆ haloalkyl group, e.g., —CF₃; —CH₂CF₃; or —CHCl₂;C₁-C₆ alkylthio; amino; mono and dialkyl amino groups; —NO₂; —CN; asulfate group, and the like.

Another embodiment of the invention relates to a glycidyl carbamatefunctional resin that is the reaction product of an isocyanate having atleast three isocyanate groups per molecule, glycidol, and an alcohol. Incertain compounds, all the isocyanate groups will react with theglycidol to form glycidyl carbamate functional compounds. In othercompounds, one or more isocyanate groups will react with the alcohol toform an alcohol-modified glycidyl carbamate compound. The glycidylcarbamate functional resin may contain both glycidyl carbamatefunctional compounds and alcohol-modified glycidyl carbamate compounds.The percentage of isocyanate groups reacting with the alcohol depends,at least partially, on the ratio of glydicol to alcohol used.

The equivalent ratio of glycidol to alcohol may range from 1:2 to 59:1,preferably 1:2 to 49:1, more preferably 1:2 to 29:1, even morepreferably from about 1:1 to about 3:1, and most preferably theequivalent ratio is approximately 2:1. The equivalent ratio may bevaried by adjusting the stoichiometric ratio of the reactants used toprepare the resins.

Resins containing alcohol-modified GC compounds have a lower viscositythan resins prepared where glycidol is the only reagent used. Formulatedin solvent-based coating compositions, these resins can be crosslinkedwith multifunctional amines or self-crosslinked at elevatedtemperatures. The pendent glycidol groups are especially effective atpromoting crosslinking.

The invention also relates to a method of making an alcohol-modifiedglycidyl carbamate resin containing glycidyl carbamate functionalcompounds, comprising the step of substituting about 5% to about 45% ofthe glycidyl groups in the glycidyl carbamate functional compounds withan alcohol. Preferred ranges include about 16% (⅙) to about 45%, about33% to about 45%, and about 16% to about 33%. The percentages are molarpercentages, based on the amount of glycidyl groups that have beensubstituted with an alcohol.

The resin may contain both alcohol-modified glycidyl carbamate compoundsand other GC-functional compounds that have not been reacted with thealcohol. For instance, the glycidol groups of certain GC-functionalcompounds may not react with the alcohol because the amount of alcoholused was sufficiently low. Alternatively, the resin may contain multiplebatches of GC-functional compounds, some of which contain glycidolgroups that have been reacted with alcohol groups, and some of whichcontain glycidol groups, none of which have been reacted with analcohol.

The GC-functional compound may be a biuret glycidyl carbamate functionalcompound, a triisocyanurate glycidyl carbamate functional compound, animinooxadiazine dione compound, a multi-functional allophanate compound(such as a trifunctional or tetrafunctional allophanate resin) having atleast three pendent glycidyl carbamate groups, or combinations thereof.Other resins having at least three glycidyl carbamate groups, such as aGC resins made from polymeric MDI, may also be suitable.

Preferred Alcohol-Modified BGC Resins

One preferred group of alcohol-modified GC resins are alcohol-modifiedBGC resins, resins of formula (II) where n is 0. Replacing a portion ofthe glycidol in the structure of the resins provides resins having lowerviscosity as well as good properties when crosslinked materials areproduced. Two sets of alcohol modified resins have been prepared. Firsta set of three BGC-functional resins were made where approximately ⅓ ofthe glycidol was replaced by either n-butanol, iso-butanol, or2-ethylhexanol. Examples of these are illustrated below.

The viscosity of the resins as-made (without solvent) as well as reducedto 80% with t-butyl acetate (t-BAc) was measured and is shown inTable 1. The viscosities of the alcohol-modified resins aresubstantially lower than the control BGC resin.

Preferred Ether Alcohol Modified BGC Resins

Another preferred group of alcohol-modified GC resins arealcohol-modified BGC resins, resins of formula (II) where n is 1 orgreater. Preferably, n is 1, 2 or 3. This second set of resins wassynthesized using ether alcohols as the modifying alcohol. Resins wereprepared replacing approximately ⅓ of the glycidol with ethylene glycolbutyl ether (EB), ethylene glycol propyl ether (EP), or diethyleneglycol butyl ether (DB). The structures are illustrated below.

The viscosity of the resins was determined as-made (˜100% solids) andafter reducing to 80% solids with t-butyl acetate (t-BAc). The data inTable 6 shows that the viscosity of the ether alcohol modified resins issignificantly lower than the control resin.

Coating Compositions of the Invention

As discussed above, the invention also relates to solvent-based coatingcompositions comprising an alcohol-modified GC compound of formula(I)-(IV), an optional curing agent, and an optional organic solvent. Thecoating compositions of the invention may be self-crosslinking. Oneembodiment of the invention is 100% solids coating composition, with orwith out a curing agent. For solvent-based coatings, thealcohol-modified GC resin containing one or more GC-functional compoundsof formulas (I)-(IV) are generally present in a coating composition ofthe invention in the amount of about 30—about 80 weight percent solidsand preferably about 60—about 70 weight percent solids. The curingagent, when present, may be used in the manner and amount known in theart. For example, the curing agent is present in the amount of about 1weight percent to about 30 weight percent and preferably about 15 to 25weight percent.

The curing agent serves to crosslink the resultant epoxy urethanecoating formed using a solvent-based coating composition of theinvention. The curing agent may be any curing agent known in the art tocure (or crosslink) epoxy resins. Suitable curing agents for use withthe compositions of the inventions include those typically employed withepoxy resins, such as aliphatic, araliphatic and aromatic amines,polyamides, amidoamines and epoxy-amine adducts. The coating may becured at ambient or elevated (e.g. about 80° C.) temperatures. Aminecuring agents typically allow the coating to cure at ambienttemperatures.

Suitable amine curing agents are those which are soluble or at leastdispersible in a coating composition of the invention. Amine curingagents known in the art include, for example, diethylenetriamine,triethylenetetramine, tetraethylene-pentamine, etc. as well as4,4′-methylene dianiline, 2,2,4- and/or2,4,4-trimethylhexamethylenediamine; 1,2- and 1,3-diaminopropane;2,2-dimethylpropylenediamine; 1,4-diaminobutane; 1,6-hexanediamine;1,7-diaminoheptane; 1,8-diaminooctane; 1,9-diaminononane;1,12-diaminododecane; 4-azaheptamethylenediamine;N,N″-bis(3-aminopropyl)butane-1,4-diamine; 1-ethyl-1,3-propanediamine;2,2(4),4-trimethyl-1,6-hexanediamin; bis(3-aminopropyl)piperazine;N-aminoethylpiperazine; N,N-bis(3-aminopropyl)ethylenediamine;2,4(6)-toluenediamine; dicyandiamine; melamine formaldehyde;tetraethylenepentamine; 3-diethylaminopropylamine;3,3″-iminobispropylamine; tetraethylenepentamine;3-diethylaminopropylamine; and 2,2,4- and2,4,4-trimethylhexamethylenediamine. Exemplary cycloaliphatic aminecuring agents include, but are not limited to, 1,2- and1,3-diaminocyclohexane; 1,4-diamino-2,5-diethylcyclohexane;1,4-diamino-3,6-diethylcyclohexane; 1,2-diamino-4-ethylcyclohexane;1,4-diamino-2,5-diethylcyclo-hexane;1,2-diamino-4-cyclohexylcyclohexane; isophorone-diamine;norbornanediamine; 4,4′-diaminodicyclohexylmethane;4,4′-diaminodicyclohexylethane; 4,4′-diaminodicyclohexylpropane;2,2-bis(4-aminocyclohexyl)propane;3,3′-dimethyl-4,4′-diaminodicyclohexylmethane;3-amino-1-(4-aminocyclohexyl)propane; 1,3- and1,4-bis(aminomethyl)cyclohexane; and1-cyclohexyl-3,4-dimino-cyclohexane. Exemplary araliphatic amines, inparticular those amines in which the amino groups are present on thealiphatic radical, include, for example, m- and p-xylylenediamine andits hydrogenation products as well as diamide diphenylmethane; diamidediphenylsulfonic acid (amine adduct); 4,4″-methylenedianiline; 2,4-bis(p-aminobenzyl)aniline; diethyltoluenediamine; and m-phenylene diamine.The amine curing agents may be used alone or as mixtures.

Preferred amine curing agents used with the coating compositions of theinvention include PACM (bis(para-aminocyclohexyl)methane), andpolyamides such as Ancamide 2353. Stoichiometry ratios of amine tooxirane of the coating compositions may be based on amine hydrogenequivalent weight (AHEW) and on weight per epoxide (WPE).

Suitable amine-epoxide adducts include, for example, reaction productsof diamines, such as ethylenediamine, diethylenetriamine,triethylenetetramine, m-xylylenediamine and/orbis(aminomethyl)cyclohexane with terminal epoxides, such as thepolyglycidyl ethers of the polyhydric phenols listed above.

Polyamide resins can also serve as curing agents for the resins.Suitable polyamide reins include those prepared through the reactionproduct of multifunctional amines with diacids. Dimer fatty acids arethe most commonly used diacids for the synthesis of polyamide resins.

Examples of solvents that may be used include, but are not limited to,mixed xylenes, toluene, Aromatic 100, Aromatic 150, acetone, methylethyl ketone, methyl amyl ketone, methyl isobutyl ketone, ethanol,n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, ethyleneglycol monobutyl ether, propylene glycol n-butyl ether, propylene glycolmethyl ether, propylene glycol monopropyl ether, dipropylene glycolmethyl ether, diethylene glycol monobutyl ether, trimethylpentanediolmono-isobutyrate, ethylene glycol mono-octyl ether, diacetone alcohol,TEXANOL™ ester alcohol (supplied by Eastman Chemical Company), ethyl3-ethoxy propionate (EEP) and tertiary butyl acetate (TBA), and thelike, as well as mixtures thereof.

The coating composition may further contain at least one coatingadditive to, for example, enhance the composition's coating efficiency.Examples of suitable coating additives include, but are not limited to,leveling and flow control agents such as silicones, fluorocarbons orcellulosics; extenders; plasticizers; flatting agents; pigment wettingand dispersing agents; ultraviolet (UV) absorbers; UV light stabilizers;defoaming and antifoaming agents; anti-settling, anti-sag and bodyingagents; anti-skinning agents; anti-flooding and anti-floating agents;and corrosion inhibitors. Specific examples of such additives can befound in Raw Materials Index, published by the National Paint & CoatingsAssociation, 1500 Rhode Island Avenue, N.W., Washington, D.C. 20005.Further examples of such additives may be found in U.S. Pat. No.5,371,148, herein incorporated by reference in its entirety.

Examples of suitable flatting agents include, but are not limited to,synthetic silica, available from the Davison Chemical Division of W. R.Grace & Company, as SYLOID™; polypropylene, available from HerculesInc., as HERCOFLAT™; synthetic silicate, available from J. M. HuberCorporation, as ZEOLEX™.

Examples of suitable viscosity, suspension, and flow control agentsinclude, but are not limited to, polyaminoamide phosphate, highmolecular weight carboxylic acid salts of polyamine amides, and alkyleneamine salts of an unsaturated fatty acid, all available from BYK ChemieU.S.A. under the ANTI TERRA™ mark. Further examples include, but are notlimited to, polysiloxane copolymers, polyacrylate solution, celluloseesters, hydroxyethyl cellulose, hydroxypropyl cellulose, polyamide wax,polyolefin wax, hydroxypropyl methyl cellulose, polyethylene oxide, andthe like.

The coating compositions of the invention may be used to form coatingson a substrate. Preferred substrates include wood, steel, aluminum,plastic, and glass. The invention relates to a method of coating suchsubstrates by applying the coating composition to the substrate. Thecoating may be applied by methods know in the art such as drawdown,conventional air-atomized spray, airless spray, roller, and brush. Forthose coating compositions containing a crosslinker, the coating may becured at ambient temperatures or above. Self-crosslinking coatingcompositions are cured at elevated temperatures, preferably at or above100° C., and more preferably at or above 150° C., to form thermosetcoatings on the particular substrate.

The following examples are given to illustrate the invention. It shouldbe understood, however, that the invention is not to be limited to thespecific conditions or details described in these examples.

EXAMPLES

Materials:

Hexamethylene diisocyanate biuret, a biuret resin condensate derivedfrom hexamethylene diisocyanate (Tolonate® HDB-LV), was provided byRhodia Inc. HDB-LV has an NCO equivalent weight of 175.44 g/eq. Glycidolwas supplied by Dixie Chemical Co. and stored refrigerated to minimizeformation of impurities. Alcohols used were 2-ethyl hexanol (EHA) (AlfaAesar), isobutanol (IsoBuOH) (Alfa Aesar) and 1 butanol (1 BuOH, BA) (J.T. Baker), ethylene glycol butyl ether (EB) (Aldrich), diethylene glycolbutyl ether (DB) (Aldrich) and ethylene glycol propyl ether (EP)(Fluka-Aldrich).

Dibutyltindilaurate (DBTDL), purchased from Aldrich, was used tocatalyze the isocyanate, glycidol and alcohol reactions to form glycidylcarbamate (GC). All the reagents were used as received without anyfurther purification.

Solvents used for the formulations were ethyl 3-ethoxy propionate (EEP)and tertiary butyl acetate (TBA) obtained from Aldrich and Ashland,respectively. The amine crosslinkers, para-aminocyclohexyl methane(PACM) and Ancamide 2353 were provided by Air Products.

Synthesis of Glycidyl Carbamate Functional Compounds

A 500 ml four neck reaction vessel with condenser, nitrogen inlet andModel 210 J-KEM temperature controller, mechanical stirrer and waterbath for heating and cooling the vessel was used for resin synthesis.The stoichiometric equivalent amounts used for the synthesis of biuretglycidyl carbamate (BGC) was 1:1 (isocyanate:glycidol) and that formodified BGC was 1:0.66:0.33 (isocyanate:glycidol:alcohol). Thus,overall isocyanate index (NCO/OH) was maintained up to 98 to 101.

For the synthesis of both BGC and alcohol modified BGC, the reactionvessel was charged with HDB-LV followed by glycidol and alcohol or etheralcohol and the reaction mixture was held at 40-45° C. After mixing for45 to 60 min, 0.03 wt % (of the reaction charge) DBTDL catalyst intertiary butyl acetate solution (1.2-1.4% wt) was added. Reaction showeda very high exotherm at 40° C. after the addition of DBTDL. After thispoint, bubbles started to form, the viscosity started to increase andthe appearance of the reaction mixture changed from transparent to milkyover the entire reaction period. Disappearance of NCO peak was monitoredby FTIR and the reaction was continued until the peak disappeared. Afterthe completion of reactions, resins were collected in glass jars.

FTIR Measurements:

FTIR measurements were performed using a Nicolet Magna-850 FTIRspectrometer. Sample aliquots were taken and coated on a potassiumbromide salt plate. Spectral acquisitions were based on 64 scans and adata spacing of 1.98 cm⁻¹. The FTIR was set for auto gain to monitorspectral ranges of 4000-500 cm⁻¹. Monitoring of changing band absorptionwas used to follow conversion during the reaction using isocyanate (2272cm⁻¹), —OH and —NH (3750 to 3000 cm⁻¹), amide (1244 cm⁻¹) and epoxide(910 to 815 cm⁻¹) bands.

NMR Characterization:

¹³C NMR was done for all of the GC resins using a JEOL (400 MHz) NMRspectrometer coupled with an auto-sampler accessory. The spectra wererun at 30° pulse angle, 1.04 sec acquisition time, 2 sec relaxationdelay, and at 24° C. with 1000 scans. All the spectra were collected bydissolving 50 to 70 mg samples in 0.7 ml CDCl₃. The spectra wereanalyzed using Delta NMR processing and control software (Version4.3.5).

Gel Permeation Chromatography:

Gel permeation chromatography (GPC) was conducted using a Waters 515HPLC solvent pump, Waters 2410 refractive index detector, Waters717-auto sampler with injection volumes of 200 μl and a flow rate of 1ml/min. The samples were dissolved in tetrahydrofuran (THF), 1 mg cm⁻³,and filtered with a 0.2 μm PTFE filter. Styragel HR and HT columns wereused for high resolution at low- and mid-ranged molecular weights,respectively. Polystyrene standards were used for calibration.

Viscosity Measurements:

Brookfield (HADVE 115 Model) and Brookfield (DV-II+Pro) instruments wereused for viscosity measurements of alcohol modified and ether alcoholmodified BGC resins respectively. About 300 g of resin was taken in a500 ml glass jars. Spindle number 7 was used with an rpm range of 0.5 to2 rpm. All the readings over a range of 10 min were averaged.

Epoxy Titration:

Epoxy equivalent weights of resins were determined by titration withhydrogen bromide (HBr) according to ASTM D1652. 0.06 to 0.8 g of resinwas dissolved in 5-10 ml of chloroform and was titrated againststandardized HBr in glacial acetic acid using crystal violate indicator.Weight per epoxy was calculated according to ASTM D 1652.

Coating Preparation:

Amine-crosslinked and self-crosslinked coating formulations were madefor coating performance study. Formulations were based on 60% solids (wt%). The solvents used for all the formulations were ethyl 3-ethoxypropionate (EEP) (20 wt %) and tertiary butyl acetate (TBA) (20 wt %).Two amine crosslinkers used were para aminocyclohexyl methane (PACM) andAncamide 2353.

Amine:epoxy equivalent ratio was maintained to 1:1 in all theformulations. Film drawdowns were made on steel panels (smooth finished,Q panels) after degreasing the panels with p-xylene. Films were drawn at8 mils using drawdown bar and kept at room temperature overnight. Thenext day, coated panels were placed in an oven at 80° C. for an hour.All the panels were kept at room temperature after curing and weretested the next day and after fourteen days. Amine-crosslinked etheralcohol modified BGC were tested after fourteen days.

For the self-crosslinked coatings, the coating film drawdowns were madein the same way as explained above. The curing of the coating films wascarried out at 150° C. for 1 hr 45 min. Coatings were kept under ambientconditions for three days before their properties were evaluated.

Coating Performance:

Konig pendulum hardness was measured following ASTM D 4366, with thevalues reported in seconds(s). Coating reverse impact resistance wasdetermined using ASTM D 2794 with a Gardener impact tester. The maximumdrop height was 43 inch with a drop weight of four pounds. Crazing orloss of adhesion was noted and inch pounds were determined at filmfinish failure. Samples that did not fail were noted as >172 in-lbs. Aconical mandrel test was also used to determine the flexibility of thecoatings (ASTM D 522). Coatings that did not crack during theflexibility test were noted as pass, those that had any signs of defectswere noted as fail. Methyl ethyl ketone (MEK) double rubs were used toassess the development of cure. A 26-ounce hammer with five-layers ofcheesecloth wrapped around the hammerhead was soaked in MEK. After 100double rubs the hammer was rewet with MEK. Once mar was achieved thenumber of double rubs was noted. The cross hatch adhesion of coating wasevaluated using Gardco cross hatch adhesion instrument following ASTM D3359. The gloss values were measured according to ASTM D 523.

TABLE 1 Viscosity of alcohol modified GC resins as made and reduced to80% with t-BAc. Viscosity As-made 80% solids in t- Viscosity BAc Resin(mPas) (mPas) BGC-BA 566,000 8,120 BGC-IBA 1,364,500 9,552 BGC-2EH1,002,666 11,173 BGC 3,209,666 23,290

The resins were crosslinked with either bis(p-amino cyclohexyl)methane(PACM) and a polyamide resin, Ancamide 2523 at a 1:1 stoichiometricratio of epoxy groups to amine active hydrogens. All coatings wereapplied to xylene-washed smooth cold rolled steel panels.

The coatings properties are given in Tables 2 and 3 for the coatingsafter curing in an oven at 80° C. The coatings have good hardness,flexibility, gloss, and adhesion. The coatings based on the alcoholmodified GC resins have improved flexibility over the control BGC resin.

TABLE 2 Properties of GC Resins crosslinked with PACM (1:1). ReverseKoning MEK Conical Cross Impact Hardness double Mandrel hatch Gloss GCResin in-lb sec rubs cm adhesion 20° 60° 85° BGC 160 135 >400 0 4B 93 98101 BGC-BA >172 70 280 0 5B 88 137 98 BGC-IBA >172 61 230 0 5B 117 146101 BGC-2EH >172 63 150 0 5B 125 149 102 Curing Conditions: Overnight atRT, then 60 min at 80° C.

TABLE 3 GC Resins crosslinked with Ancamide 2353 (1:1). Reverse KoningMEK Conical Cross Impact Hardness double Mandrel hatch Gloss GC Resinin-lb sec rubs cm adhesion 20° 60° 85° BGC 132 90 >400 0 4B 128 148 40BGC-BA >172 56 150 0 5B 127 152 102 BGC-IBA >172 64 170 0 5B 128 144 101BGC-2EH >172 81 160 0 5B 117 148 99 Curing Conditions: Overnight at RT,then 90 min at 80° C.

After the coatings aged for an additional 13 days at ambient, theproperties were measured again. The properties are listed in Tables 4and 5. The coatings all maintained their good adhesion, hardness andgloss. Solvent resistance was improved, indicating that additionalcuring had occurred.

TABLE 4 GC Resins crosslinked with PACM (1:1). Reverse Koning MEKConical Cross Impact Hardness double Mandrel hatch Gloss GC Resin in-lbsec rubs cm adhesion 20° 60° 85° BGC 116 168 >500 0 5B 77 120 96 BGC-BA116 134 >500 0 3B 89 134 96 BGC-IBA 140 134 >500 0 3B 125 148 99 BGC-2EH128 130 >500 0 4B 122 147 99 Curing Conditions: Overnight at RT, then 60min at 80° C. plus 13 days ambient.

TABLE 5 GC Resins crosslinked with Ancamide 2353 (1:1). Reverse KoningMEK Conical Cross Impact Hardness double Mandrel hatch Gloss GC Resinin-lb sec rubs cm adhesion 20° 60° 85° BGC 36 121 >500 0 0B 127 148 99BGC-BA 28 146 >500 0 4B 79 120 81 BGC-IBA 88 90 >500 0 1B 126 148 99BGC-2EH 44 102 >500 0 2B 114 141 98 Curing Conditions: Overnight at RT,then 90 min at 80° C. plus 13 days ambient.

TABLE 6 Viscosity of ether alcohol modified BGC resins as- made (~100%solids) and reduced to 80% in t-BAc. As-made 80% Solids in t-BAcViscosity Viscosity Viscosity rel. to Viscosity rel. to Resin (mPa · s)BGC, % (mPa · s) BGC, % BGC 5,430,000 — 174,000 — BGC-EB 1,350,000 2520,240 12 BGC-EP 698,000 13 17,040 10 BGC-DB 475,000 9 9520 5.5

Similarly, the ether alcohol modified resins (Table 6) were crosslinkedwith PACM and Ancamide crosslinkers and allowed to cure under ambientconditions for almost two weeks before determination of physicalproperties. As seen in Tables 7 and 8, the coatings based on the etheralcohol modified resins have good solvent resistance, adhesion, andgloss. The flexibility of the ether alcohol resins is improved over thatof the control BGC resin, while the hardness is lower.

TABLE 7 PACM crosslinked ether alcohol modified BGC Resins ReverseKoning Conical Impact Hardness MEK Mandrel Cross hatch Gloss GC Resin in· lb sec double rubs cm adhesion 20° 60° 85° BGC 116 168 >400 0 5B 77120 96 BGC EB >172 85 >400 0 5B 125 149 100 BGC DB >172 78 >400 0 5B 102142 98 BGC EP >172 82 >400 0 5B 123 148 100 Curing Condition: 1 hr at80° C. and kept at room temperature for 13 days before tests werecarried out Formulation: (1:1 = BGC:PACM), 20% tert butyl acetate (TBA),20% ethyl 3 ethoxy propionate (EEP), induction time before filmdrawdown: 15-20 min (Bubbles appearing during mixing disappeared duringthis time)

TABLE 8 Ancamide 2353 crosslinked ether alcohol modified BGC ResinsReverse Koning Conical Impact Hardness MEK Mandrel Cross hatch Gloss GCResin in · lb sec double rubs cm adhesion 20° 60° 85° BGC 36 121 >400 00B 127 148 99 BGC EB >172 70 >400 0 4B 131 150 97 BGC DB >172 53 >400 04B 128 149 96 BGC EP >172 51 >400 0 4B 126 149 95 Curing Condition: 1 hrat 80° C. and kept at room temperature for 13 days before tests werecarried out Formulation: (1:1 = BGC:Ancamide 2353), 20% tert butylacetate (TBA), 20% ethyl 3 ethoxy propionate (EEP), induction timebefore film drawdown: 15-20 min (Bubbles appearing during mixingdisappeared during this time)Self-Crosslinking of Alcohol-Modified GC Resins

The alcohol and ether alcohol modified BGC resins were self crosslinkedat 150° C. Coating properties are shown in Tables 9 and 10. All of theself-crosslinked coatings had good gloss and excellent adhesion.Flexibility of the coatings was good, with the ether alcohol modifiedresins yielding better flexibility than the alcohol modified resins.

TABLE 9 Properties of self-crosslinked alcohol modified BGC resins.Reverse Koning MEK Conical Cross Impact Hardness double Mandrel hatchGloss GC Resin in.lb sec rubs cm adhesion 20° 60° 85° BGC >172 193 >4000 5B 112 141 93 BGC 1 BA >172 71 150 0 5B 99 127 85 BGC IBA 72 134 100 05B 118 144 96 BGC 2EH >172 41 95 0 5B 120 145 97 Curing condition:Coatings on Q panels kept over night at room temperature and the nextday all the formulations were cured at 150° C. for 1 hr and 45 min.Coatings kept overnight after oven curing and properties checked afterthree days. Formulation: 20% TBA and 20% EEP, film drawdown at 8 mils,steel panel (Smooth finish Q panels) washed with xylene.

TABLE 10 Properties of self-crosslinked ether alcohol modified BGCresins. Reverse Koning MEK Conical Impact Hardness double Mandrel Crosshatch Gloss GC Resin in.lb sec rubs cm adhesion 20° 60° 85° BGC 148175 >400 0 5B 103 140 93 BGC EB >172 46 150 0 5B 119 145 99 BGC DB >17224 110 0 5B 93 126 87 BGC EP >172 61 120 0 5B 120 145 97 Curingcondition and formulation: All the formulation, drawdown and curingconditions were the same as that for alcohol modified BGC selfcrosslinked coatings except BGC kept for 1 hr at 150° C. Both theformulations kept at room temperature for 20 min after solvent mixing.Film drawdowns were taken after this time.

The experiments above demonstrate that substituting approx. ⅓ of theglycidol with an alcohol in the BCG resin resulted in a significantreduction in viscosity and an increase in the flexibility of aminecrosslinked coatings.

Next, a series of alcohol-modified BGC resins were synthesized with arange of alcohol substitution to determine the effect of the level ofalcohol substitution on viscosity and performance properties. Since thebase isocyanate polymer is only about 50% of the trifunctional specieswith additional higher functionality oligomers, BCG resins having agreater than ⅓ substitution of glycidol were analyzed.

A series of BGC-EP resins were synthesized with a range of EP (ethyleneglycol propyl ether) substitution for the glycidol. The epoxy equivalentweight increases systematically, as expected. See Table 3. The viscosityof the resins also decreases as the amount of alcohol modificationincreases. See FIG. 1.

TABLE 11 Epoxy equivalent weight of alcohol modified BGC resins. ResinEEW (gm/eq) Visc (mPa · s) BGC 265 3,500,000 BGC-EP 15% 336 1,300,000BGC-EP 25% 330 808,000 BGC-EP 33% 355 455,000 BGC-EP 40% 380 434,000BGC-EP 45% 465 430,000

Coatings were prepared from these resins using two different aminecrosslinkers: PACM (p-aminocyclomethane) and Ancamide 2353, a polyamideresin. Epoxy-to-amine active hydrogen ratio was 1:1. The coatings weredrawn down on cleaned, untreated steel panels and cured in an oven at80° C. for 1 hour. Coatings properties are provided in Tables 12 and 13.

TABLE 12 Performance of BGC-EP resins crosslinked with PACM. ReverseKönig MEK Conical Cross Impact Hardness double Mandrel hatch Gloss GCResin in.lb Sec rubs cm adhesion 20° 60° 85° BGC   116 168 >400 0 5B 77120 96 (t = 80) (t = 78) (t = 25) (t = 90) (t = 80) BGC-EP 15%   104120 >400 0 5B 123 160 108 (t = 75) (t = 76) (t = 85) (t = 76) (t = 80)BGC-EP 25%   112 130 >400 0 5B 58 160 112 (t = 61) (t = 66) (t = 69) (t= 66) (t = 80) BGC-EP 33% >172   82 >400 0 5B 123 148 100 (t = 44) (t =44) (t = 30) (t = 38) (t = 77) BGC-EP 40% >172   81    80 0 5B 162 164115 (t = 75) (t = 69) (t = 69) (t = 69) (t = 77) BGC-EP 45% >172   68   35 0 5B 151 170 103 (t = 76) (t = 70) (t = 74) (t = 70) (t = 81) t =average film thickness in μm, gloss taken on glass panels, other testscarried out on smooth finished steel panels (Q panel, type QD)

TABLE 13 Performance of BGC-EP crosslinked with Ancamide 2353. ReverseKönig MEK Conical Cross Impact Hardness double Mandrel hatch Gloss GCResin in.lb Sec rubs cm adhesion 20° 60° 85° BGC    36 121  >400 0 0B127 148 99 (t = 63) (t = 63) (t = 63) (t = 34) (t = 63) BGC-EP 15%   12078 >400 0 5B 166 167 117 (t = 75) (t = 76) (t = 85) (t = 76) (t = 80)BGC-EP 25% >172 71 280 0 5B 163 166 115 (t = 61) (t = 66) (t = 69) (t =66) (t = 80) BGC-EP 33% >172 51 >400 0 4B 126 149 95 (t = 44) (t = 44)(t = 46) (t = 49) (t = 44) BGC-EP 40% >172 46    50 0 5B 166 114 115 (t= 75) (t = 69) (t = 69) (t = 69) (t = 77) BGC-EP 45% >172 44    35 0 5B156 152 114 (t = 76) (t = 70) (t = 74) (t = 70) (t = 81) t = averagefilm thickness in μm, gloss taken on glass panels, other tests carriedout on smooth finished steel panels (Q panel, type QD).

For both crosslinkers, the flexibility of the coatings increases withincreasing alcohol substitution. In addition, hardness systematicallydecreases. Conical mandrel flexibility is good for all of the coatings.MEK double rubs remain high until 33% substitution is exceeded and thendeclines; this result is consistent with a significant fraction of GCmolecules being less than difunctional and not forming a good network.

The coatings were also analyzed using dynamic mechanical thermalanalysis (DMTA), differential scanning calorimetry (DSC), andthermogravimetric analysis (TGA). DMTA data was used to determine thecrosslink density and the results are plotted in FIG. 2. The crosslinkdensity systematically decreases with the decrease in epoxyfunctionality of the resins, as expected.

DSC T_(g) values of the coatings are shown in Table 14. The T_(g)decreases systematically as the functionality of the GC resinsdecreases. This is believed to be caused by both the decreasingcrosslink density and the decrease in crosslinker content in thecoatings.

The TGA data for the coatings is shown in FIGS. 3 and 4. These studiesshow that the coatings with the lowest crosslink density have the bestthermal stability.

TABLE 14 DSC T_(g) of BGC-EP coatings. BGC-EP T_(g) (° C.) Coatings PACMA-2353 BGC 85 55 BGC-EP 15% 71 49 BGC-EP 25% 65 34 BGC-EP 33% 55 40BGC-EP 40% 36 22 BGC-EP 45% 34 22

The claimed invention is:
 1. A solvent-based coating compositioncomprising an alcohol-modified glycidyl carbamate compound of formula(I), (II), (III), or (IV):

wherein: R2 is independently an optionally substituted, divalent C1-C15alkyl, an optionally substituted divalent C3-C15 cycloalkyl, or adivalent substituent selected from the group consisting of

X represents either the glycidyl group:

or an alkyl group based on an alcohol, represented as:

wherein at least two of the X moieties are represented by the glycidylgroup; n ranges from 1-50; m ranges from 1-15; and R3 is independentlyan optionally substituted C1-C22 alkyl.
 2. The coating composition ofclaim 1, wherein R2 is a divalent C3-C8 alkyl.
 3. The coatingcomposition of claim 1, wherein R3 is a C1-C6 alkyl.
 4. The coatingcomposition of claim 3, wherein R2 is —(CH2)6- and R3 is a C1-C3 alkyl.5. The coating composition of claim 1, wherein R3 is a C3-C10 alkyl. 6.The coating composition of claim 1, wherein R2 is —(CH2)6- and R3 is aC4-C8 alkyl.
 7. The coating composition of claim 1, wherein the compoundis represented by formula (I) or (II).
 8. The coating composition ofclaim 1, wherein the compound is represented by formula (IV).
 9. Thecoating composition of claim 1, wherein m ranges from 1-4.
 10. Thecoating composition of claim 1, further comprising one or more curingagents, optionally other glycidyl carbamate-functional compounds,optionally one or more organic solvents, and optionally one or morecoating additives.
 11. The coating composition of claim 10, wherein thecuring agent is an amine curing agent.
 12. The coating composition ofclaim 11, wherein the amine curing agent isbis(paraaminocyclohexyl)methane (PACM), a polyamine, or combinationsthereof.
 13. A method of coating a substrate with a solvent-basedcoating composition, comprising the step of applying the coatingcomposition of claim 1 to a substrate.
 14. The method of claim 13,wherein the substrate is selected from the group consisting of wood,steel, aluminum, plastic, and glass.
 15. The method of claim 13, whereinthe coating composition comprises at least one curing agent, optionallyother glycidyl carbamate-functional compounds, optionally one or moreorganic solvents, and optionally one or more coating additives.